There is no longer a threat that a Springfield budget stalemate will keep Chicago Public Schools closed this fall. Lawmakers funneled enough money to help CPS lurch through the upcoming school year. CPS CEO Forrest Claypool told principals Wednesday that they'll still "need to do more with less." But he promised that classrooms will be protected from even deeper spending cuts for the upcoming school year.

That leaves only one threat that could slam shut Chicago's school doors this fall: a teachers strike.

CPS and the Chicago Teachers Union are grinding into the second year of negotiations over a new teachers contract. Educators decided not to strike at the end of the last school year, reserving the option of a classroom walkout this autumn if a deal isn't reached.

We haven't heard CTU's latest demands, but the union is likely to exploit the cascade of cash from Springfield to insist that CPS open the till and fork over the cash.

CPS leaders can't — shouldn't — cave.

Why? Because Springfield rescued CPS from dramatic classroom cuts, but the district still needs to scrounge up at least $300 million to balance its fiscal 2017 budget, due for release in August. The school system still faces huge, $700 million-ish teachers pension payments this year and annually into the future. It still has too much real estate to serve its dwindling number of students. And its credit is maxing out.

Years of CPS budgets heavy on high-cost borrowing — and light on cuts and efficiencies — have kept the system from stabilizing its finances so that it can focus on educating students, not fending off the never-ending crises.

Which brings us back to the long-running contract talks and the possible teachers strike.

Let's review the details of the deal on the table last winter. In it, CPS:

•Offers teachers a generous 8.75 percent base salary increase over four years.

•Requires teachers to accept a phaseout of a 7 percent pension payment pickup that the district no longer can afford. (The district still would pick up the employer's share into the pension fund but asks employees to pay their share.)

•Allows teachers to continue to receive "step and lane" raises that reward those who earn more degrees or add a year of seniority. That's worth, on average, a 1.6 percent annual pay bump, the district says.

That's the deal that Chicago Teachers Union President Karen Lewis praised as a "serious offer."

It's the same deal approved last April by independent fact-finder Steven Bierig, who had been summoned by law to attempt to broker a compromise. Bierig called that deal "an extremely carefully balanced document that sought to protect, and indeed did protect, the core interests of both parties."

But the union's Big Bargaining Team, a group of about 40 union members that helps guide union demands, overruled Lewis, scuttled the deal and pressed its demands against a nearly insolvent district poised to collapse.

Now Springfield and Gov. Bruce Rauner have done their part to rescue CPS. They came through with tens of millions in fresh funding.

Chicago taxpayers will do their part too: The budget deal allows the Board of Education to hike property taxes by about $250 million for the district. (And Mayor Rahm Emanuel will likely take the brunt of taxpayer ire over that.)

The district expects to save $45 million from job cuts and other efficiencies in the 2017 budget year.

Everyone has contributed to the CPS rescue. Except, so far, 25,000 or so CTU members, most of them educators.

Ms. Lewis, what role will you and your union choose? You can agree to pay your own way on pensions and thus help restore the system to a more even keel for the future. Or you can insist on another budget-bursting, perk-bloated contract that the district can't afford, locking in another fiscal meltdown and more threats of classroom disruptions in the future.

Your move, Chicago teachers. Think of your students and how to help the system guarantee them the best education year after year. Or think only of ... yourselves.